One of the defining elements of metal is the overdriven aggression of it, but there have always been bands willing to go beyond the primal rush of the power chord and take the form to more inventive, more technical, more progressive places. Many bands have dabbled with proggy strokes, from Iron Maiden on their lengthier compositions to Metallica on the relatively sprawling and complex …And Justice For All. For this list, though, we’re looking only at albums that go the whole prog-metal hog. And it’s progressive metal, not prog rock, so you won’t find the likes of Porcupine Tree, The Mars Volta or even Pink Floyd releasing inflatable pigs here.
That said, progressive metal remains a broad and not always easy to define concept. Where do the boundaries lie between prog-metal and experimental, avant-garde and post-metal? And what of the intensely technical mathcore and djent scenes (which we’re not covering here as they’re pretty much their own things at this point)? Genre lawyers can argue the toss about what’s been left out, but here are 13 bona fide prog-metal classics to take you on a musical journey…